MILAN - Water is essential for human life. It represents between 50 and 70% of our body weight and it is crucial for most of our vital body functions.  Dehydration can cause several disorders, from stress to hot flushes. A headache is one for the first signs that our body sends us to tell us to drink more.

The body loses water continuously

When we are dehydrated, we first feel thirsty and tired. This leads to a state of bad temper and to mental and physical decline. Our body loses water continuously through breath, urine, faeces and the skin. Most people that maintain an optimal state of hydration manage to do so thanks to drinking water in combination with a balanced diet, with plenty of fruit and vegetables.

What happens when we are dehydrated?

Research conducted at the Institute of Medicine demonstrates that already when we reach 1% dehydration, our mood worsens, together with our attention, memory and motor coordination. Furthermore, it seems that dehydration can lead to a lowering of cerebral tissue, thus reducing the brain's volume and temporarily affecting cellular functions. Blood is also affected by the lack of water, becoming more concentrated, which increases the heart rate and as a consequence blood pressure. In the kidneys, on the other hand, the lack of intake of liquids triggers an alarm that makes people urinate less.

How much does one need to drink?

The water requirements of people vary significantly depending on different factors: body composition, metabolism, diet, climate and clothing. According to some studies, an adequate water intake for adult men and women is respectively 3.7 and 2.7 litres per day. Around 80% of liquids taken in during the day must derive from water, with the remaining 20% from food. 

di Alessandro Conte